Processes for the purification of liquids and apparatus for carrying out such processes are known. In the systems, liquids can be subjected to a voltage field causing separation of cations and anions and precipitation of the latter as a solid matter in extremely fine dispersion.
In addition to this electrolytic process, the liquid is often passed through an ion exchanger increasing the throughput rate of purified liquid. The chemical process of passing of the liquid through the ion exchanger also results in precipitation of a solid material. The increase of volume of treated liquid results in the continuous performance of the ion exchange process because the liquid flow does not have to be interrupted.
A combination of electrolytic and chemical processes have been described in German Patent document 33 41 242 disclosing the removal of oxygen from an aqueous solution. According to the teaching of the application the liquid flow passes through a permeable spatially extending ion exchanger. Simultaneously with the chemical treatment, the liquid is subjected to an electrical field propagating radially from concentrically mounted electrodes and extends coaxially with respect to the liquid flow. The oxygen produced in the ion exchange process is removed by appropriately mounted pipes.
German Patent document 38 05 813 discloses a loaded ion material which can be treated electrolytically, chemically or electrochemically without having to be removed from the apparatus. In this case the ion exchange material is subjected, for example, to a pulsating alternating electrical field or ionizing chemicals.
A basic drawback of all of the described above processes is that the solid material remains present so that it is possible for the precipitated solids to revert to the original state in a subsequent chemical or electrochemical process. This is undesirable and should be avoided.
Still another problem of the known devices is that they are incapable of reducing cations and anions with the same ion exchanger.